fix: resolve 6 backend compilation errors

cfc-backend/src/main/java/com/etotem/cfc/service/ContentRecommendService.java

@@ -1,6 +1,7 @@
 package com.etotem.cfc.service;
 
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
 import com.etotem.cfc.dto.RecommendItemVO;
 import com.etotem.cfc.dto.RecommendRequestDTO;
 import com.etotem.cfc.entity.*;
@@ -131,8 +132,9 @@ public class ContentRecommendService {
         Set<Long> readArticleIds = new HashSet<>();
         if (childId != null) {
             List<ArticleReadingRecord> records = articleReadingRecordMapper.selectList(
-                    new LambdaQueryWrapper<ArticleReadingRecord>()
-                            .eq(ArticleReadingRecord::getChildId, childId));
+                    new QueryWrapper<ArticleReadingRecord>()
+                            .eq("child_id", childId)
+                            .select("DISTINCT article_id"));
             for (ArticleReadingRecord r : records) {
                 if (r.getArticleId() != null) readArticleIds.add(r.getArticleId());
             }
@@ -190,9 +192,10 @@ public class ContentRecommendService {
         // 获取已存在的任务（用于去重）
         Set<Long> articleSourceIds = new HashSet<>();
         List<Task> existingTasks = taskMapper.selectList(
-                new LambdaQueryWrapper<Task>()
-                        .eq(Task::getChildId, childId)
-                        .in(Task::getStatus, "pending", "completed"));
+                new QueryWrapper<Task>()
+                        .eq("child_id", childId)
+                        .in("status", "pending", "completed")
+                        .select("id", "source_type", "source_id"));
         for (Task t : existingTasks) {
             if ("article".equals(t.getSourceType()) && t.getSourceId() != null) {
                 articleSourceIds.add(t.getSourceId());
@@ -467,12 +470,12 @@ public class ContentRecommendService {
     /** 获取家庭已购商品ID */
     private Set<Long> getPurchasedProductIds(Long familyId, Long userId) {
         Set<Long> ids = new HashSet<>();
-        LambdaQueryWrapper<ProductOrder> wrapper = new LambdaQueryWrapper<ProductOrder>()
-                .eq(ProductOrder::getStatus, "paid");
+        QueryWrapper<ProductOrder> wrapper = new QueryWrapper<ProductOrder>()
+                .eq("status", "paid");
         if (familyId != null) {
-            wrapper.eq(ProductOrder::getFamilyId, familyId);
+            wrapper.eq("family_id", familyId);
         } else if (userId != null) {
-            wrapper.eq(ProductOrder::getBuyerId, userId);
+            wrapper.eq("buyer_id", userId);
         } else {
             return ids;
         }
@@ -495,16 +498,18 @@ public class ContentRecommendService {
             }
             if (!memberUserIds.isEmpty()) {
                 List<ActivityRegistration> regs = activityRegistrationMapper.selectList(
-                        new LambdaQueryWrapper<ActivityRegistration>()
-                                .in(ActivityRegistration::getUserId, memberUserIds));
+                        new QueryWrapper<ActivityRegistration>()
+                                .in("user_id", memberUserIds)
+                                .select("distinct activity_id"));
                 for (ActivityRegistration r : regs) {
                     ids.add(r.getActivityId());
                 }
             }
         } else if (userId != null) {
             List<ActivityRegistration> regs = activityRegistrationMapper.selectList(
-                    new LambdaQueryWrapper<ActivityRegistration>()
-                            .eq(ActivityRegistration::getUserId, userId));
+                    new QueryWrapper<ActivityRegistration>()
+                            .eq("user_id", userId)
+                            .select("distinct activity_id"));
             for (ActivityRegistration r : regs) {
                 ids.add(r.getActivityId());
             }